Avocados in some parts of coastal California have been blooming. Some of them got hit by the cold weather in the first part of February. In the coldest areas there was a little bit of new leaf damage, but this has been minimal.
Some browning of some flowers and stems (pedicels - the little stalks the connect the flowers to the larger raceme/panicle) may have occurred, but I haven't heard of major flower damage.
It's early days for flowering, though, and most ‘Hass' trees are not very far along, but seem like they area about to burst. A recent visit on a 40 acre farm in Saticoy had trees in a whole range of stages, some with no flowers pushing, some with panicles just starting to open individual flowers and many trees on their north sides' completely quiet. Many are still just pushing into the cauliflower stage,
which is the ideal time is for applying Pro-Gibb to improve fruit set in healthy orchards.
Application time is when 50% of the trees in the block have 50% of their bloom in the cauliflower stage. This is a judgment call when there can be such huge variation in bloom across and orchard. It's going to be a best estimate call for when to do the application. As usual with a new technology/practice don't apply to the whole orchard so that you can see whether the application is warranted.
For a more detailed discussion of gibb application, read Carol Lovatt's article: